A quantity discount is an incentive offered to a buyer that results in a decreased cost per unit of goods or materials when purchased in greater numbers. A quantity discount is often offered by sellers to entice customers to purchase in larger quantities.

The seller is able to move more goods or materials, and the buyer receives a more favorable price for them. At the consumer level, a quantity discount can appear as a BOGO (buy one, get one discount) or other incentives, such as buy two, get one free.